Alibaba Group Holding Ltd and Softbank Corp are in advanced talks with Blackstone Group LP and Bain Capital LLC about making a bid for all of Yahoo! Inc, Bloomberg reported Thursday, citing three people with knowledge of the matter.

A bid may value Yahoo at more than $20 a share because of tax savings tied to the Internet company's stakes in Alibaba and Yahoo Japan, said two of the people, who declined to reveal their names because the discussions are private.

Yahoo shares advanced 6.9 percent to $16.79 in extended trading.

Yahoo's board is meeting to discuss offers it received for a minority stake in the Sunnyvale, California-based company from bidders including TPG Capital and a group led by Silver Lake, people familiar with the matter said this week. Silver Lake's bid valued Yahoo at about $16.60 a share, the sources said. TPG Capital's offer was higher, they said.

Some Yahoo investors say they would prefer the company be sold in its entirety, at a higher price. "It definitely has to be much higher than $16.60," said Di Zhou, a Santa Fe, New Mexico-based analyst at Thornburg Investment Management, which oversees about $80 billion in assets, including Yahoo shares.

While the Alibaba group has prepared financing for a possible offer, it hasn't decided on a final price or whether to proceed, the people said. The group would prefer to be invited to bid rather than going hostile, one person said. Alibaba hasn't informed Yahoo of its possible bid, this person said.